Should vitamin D supplements be recommended to prevent chronic diseases?

Rapid Response:

Dr. Haakon E. Meyer and colleagues state firmly in their article that “vitamin D supplementation (…) combined with calcium may be recommended to prevent fractures in elderly people, according to evidence from a Cochrane review and updated nutritional recommendations for vitamin D intake in the general population” (1). However, in our opinion benefits and harms of combined supplements for an overall community-dwelling people are not so clearly in favour of pharmacological treatment.

This is because the main outcome to have in mind should not be a decrease in non-vertebral fractures or any type of fracture, as the invoked Cochrane review claims (2) (DIPART study (3) was later included in this review). Instead, hip fracture should be underlined as the most relevant endpoint in terms of morbi-mortality and population quality of life (4). Taking this into account, even if a small reduction in hip fracture risk has been shown in the overall population with calcium and vitamin D combination, it must be recognised that most of benefits were due to the results in the high-risk population subgroup (9 fewer hip fractures per 100 older adults-year (95% CI, 2 to 14) (2). Thus, high-risk population could be expected to benefit from vitamin D plus calcium supplements to some extent, in terms of fewer hip fractures, while the risk-benefit ratio in healthy low-risk population is uncertain and overtreatment might occur. We all need to be aware of these data in order to properly address drug therapy to the right target.